Carpets comprising bulked continuous filament (BCF) and/or staple yarns are made in a variety of manners known to those skilled in the art. Typically, a number of yarns are cable twisted together (about 3.5 to 6.5 turns per inch (about 1.38 to 2.56 turns/cm) and heat-set in a device (such as an autoclave) and then tufted into a primary backing. Latex adhesive and a secondary backing are then applied. Cut pile style carpets having a pile height between about 0.25 to 1 inches (about 0.64 to 2.54 cm), or loop pile style carpets having a pile height between about 0.125 to 0.375 inches (about 0.318 to 0.953 cm), can be made with BCF yarns. Typical carpet weights are between about 25 to 90 ounces per square yard (about 847.8 to 3051.9 g/m2).
Carpets made from poly(trimethylene terephthalate) (“3GT” or “PTT”) yarns have built-in stain resistance comparable to poly(ethylene terephthalate) (“2GT”) yarns and satisfactory texture retention and resistance to crushing. Further, carpets comprising 3GT yarns have superior softness and dye capability compared to carpets made from 2GT yarns, and superior softness compared to carpets made from nylon.
Polyester carpets are generally dyed with disperse dyes with the aid of a carrier, which is a compound that functions to open the structure of a polyester to enhance dyeability with disperse dyes. Carrier is particularly useful to enhance 3GT dyeability in dark shades during continuous dyeing.
Antistatic agents are in general well-known to those of ordinary skill in the art and, in the context of carpets, are generally a topically applied chemical typically of a hygroscopic nature to reduce static levels. Antistatic agents are useful to reduce 3GT static levels for more demanding applications, such as computer rooms and commercial carpets, under American Association of Textile Chemists and Colorists (AATCC) Test Method 134 (GSA).
Carrier (and dye) and/or antistatic agent are generally applied to the carpet post-tufting.
Ideal, laboratory scale carpets produced from 3GT yarns are known to have a Class I flammability rating without the need for flame retardants. These ideal, laboratory scale carpets also do not contain carrier and antistatic agents.
Carpets comprising 3GT yarns used in real world applications, however, typically contain both carrier and antistatic agent, and have not been found to meet this flammability requirement without the use of significant amounts of flame retardants. Flame retardants, while improving the flammability rating of a carpet, are economically disadvantageous, and it would be desirable to minimize the amount of flame retardant necessary while still retaining suitable flammability ratings.